Fix removing UTF-8 BOM from file

Author: SteveL-MSFT

dsc/locales/en-us.toml

@@ -135,3 +135,4 @@ failedToGetParentPath = "Error reading config path parent"
 dscConfigRootAlreadySet = "The current value of DSC_CONFIG_ROOT env var will be overridden"
 settingDscConfigRoot = "Setting DSC_CONFIG_ROOT env var as"
 stdinNotAllowedForBothParametersAndInput = "Cannot read from STDIN for both parameters and input."
+removingUtf8Bom = "Removing UTF-8 BOM from input"

dsc/src/util.rs

@@ -475,7 +475,13 @@ pub fn get_input(input: Option<&String>, file: Option<&String>, parameters_from_
         } else {
             match std::fs::read_to_string(path) {
                 Ok(input) => {
-                    input
+                    // check if it contains UTF-8 BOM and remove it
+                    if input.as_bytes().starts_with(&[0xEF, 0xBB, 0xBF]) {
+                        info!("{}", t!("util.removingUtf8Bom"));
+                        input[3..].to_string()
+                    } else {
+                        input
+                    }
                 },
                 Err(err) => {
                     error!("{}: {err}", t!("util.failedToReadFile"));

dsc/tests/dsc_args.tests.ps1

@@ -262,6 +262,22 @@ resources:
         $stderr | Should -Match '.*?--file.*?'
     }
 
+    It 'file containing UTF-8 BOM should be read correctly' {
+        $yaml = @'
+            $schema: https://aka.ms/dsc/schemas/v3/bundled/config/document.json
+            resources:
+            - name: Echo
+              type: Microsoft.DSC.Debug/Echo
+              properties:
+                output: hello
+'@
+        Set-Content -Path "$TestDrive/utf8bom.yaml" -Value $yaml -Encoding utf8BOM
+        $out = dsc config get --file "$TestDrive/utf8bom.yaml" | ConvertFrom-Json
+        $LASTEXITCODE | Should -Be 0
+        $out.results[0].type | Should -BeExactly 'Microsoft.DSC.Debug/Echo'
+        $out.results[0].result.actualState.output | Should -BeExactly 'hello'
+    }
+
     It 'Get operation on the adapter itself should fail' {
         dsc resource get -r Microsoft.DSC/PowerShell 2> $TestDrive/tracing.txt
         $LASTEXITCODE | Should -Be 2